Water tube steam generator



Sept. 26, 1933. H. c. EGLOFF WATER TUBE STEAM GENERATOR nllllllll lllllll 1 i I .J Inn/ENTE Patented Sept. 26, 1 933 UNITED STATES FATE } 1,928,010 Y WATER TUBE STEAM GENERATOR Hans C. Eglotfl Bern, Switzerland, assignor to I the firm of Sulzer Frres Socit Anonyme, Winterthur, Switzerland Application January 28, 1932, Serial No. 589,402, and in Switzerland February '7, 1931 7 Claims.

This invention relates to water tube steam generators of the high pressure type in which the working medium is conveyed through a system of evaporating tubes connectedin parallel.

According to the present invention not only the main supply of working medium to the inlet end of the tube system but also additional supplies introduced at intermediate points in the several tubes are regulated in accordance with the tem- 1 perature of the steam generated. Conveniently the regulation is effected in accordance with. the temperature of the steam generated in the individual tubes.

Two constructions of water tube steam genera- 1 tor according to the present invention are illustrated diagrammatically and by way of example i in Figures 1 and 2 respectively of the accompanying drawings.

. In the construction illustrated in'Figure 1 the steam generator includes a set of preliminary heating tubes 1a, 1b, 10 connected in parallel and to a main feed pipe through which liquid medium is fed by a pump 2, the preliminary heating tubes having a common delivery pipe 3. A second set of tubes la, 4b, 4c, 4d are connected in parallel and to the pipe 3, these tubes delivering superheated steam to a common steam supply pipe 5 which leads to the point or points of consumption.

with heat by any suitable means.

A series of temperature-controlled devices 6a, 6b,- 6c, 6d, eachv associated with one of the tubes 4a, 4b, 4c and 4d, control additional supplies oi working medium introduced fromrthe main feed pipe through pipes 7a, 7b, 7c, 7d so that this ad-. ditional medium is fed to each tube at a point therein where the medium is already in the evaporated state. Each of the devices 60., 6b, 6c, 601 is to control a throttling device or valve 10 disposed in the pipe through which additional medium is fed to the corresponding tube. In addition, each of the temperature-controlled devices 611, 6b, 6c, 6d is connected by a pipe 11 to a servoof the tubes 4a, 4b, 4c, 411 is individually con- .The tubes 1a, 1b, 1c and 4a, 41),40, 4d are supplied r v valve 13 and thereby'reduce the quantity of medium introduced to the first set of tubes 1a',-1b,' 1c) devices 6a, 6b, 6c, 6d and valves '10 are returned- 71 connected by a pipe 8 to a servomotor 9 adapted motor 12 which is adapted to control a throttling 6c, 6d actuate the valves 10 so as to increase trolled by the temperature-controlled device as-- sociated with that tube, the temperature of the steam delivered will be substantially the-same for impulse to the servomotor l2 and thereby adjust the valve 13 so as to increase thequantity of 1 medium introduced to the first setof tubes 1a, 1b, 1c, the temperature of the steam generated by the tubes 4a, 4b, 4c, 411 being thus'reduced until I the control devices 6a, 6b, 6c, 6d and valves 10 and 13 are returned to their normal positions. I

When the temperature of the superheated steam generated by the tubes 4a, 4b, 4c, 4d drops below a predetermined value the temperaturecontrolled devices 6a, 6b, 6c, 6d will actuate the valves 10 so as to decrease thequantity of additional medium introduced through the pipes 7a,

" 7b; 7c; .7d untilthe temperatureof the generated steam is again restored to the desired value. If, however, the temperature of the generated steam is still below that desired when the limits oro' eration of thevalves 10 havebeen'r'eached the control devices 6a, 6b, 6c; 6d'will transmit an impulse to the servomotor 12 so as'to'adju'st-the until the temperature'of' the generated---,stearr'1I has been restored to the desired value and'the.

to their normal positions. 7

In the construction illustrated in Figure 2 "a temperature-controlled device l l -influenced in accordance with the temperature of the medium 1 delivered to the pipe 3 by the preliminary heating tubes 10., 1b, 1c is adapted to control the deliveryof a main feed pump 2 which supplies liquid medium to the inlet end of the system. Additional'working medium is introduced to each-of the individual tubes 4a, 4b, 4c, 4d by means" of a pumping device 16, each of these pumping-devicesbeing in turn independently supplied with medium through-the pipes Fm-7b, 7c, 7d. In this construction each of the temperature-con trolled devices 611, 6b, 6c, 6d is adapted to control the delivery of the pumping device 16 asso- 1 ciated with the corresponding tube sothat when the temperature of the steam generated by the tubes 4a, 4b,- 4c, 4d rises above the desired value the temperature-controlled devices 6a, 6b,6c, 6d regulate the delivery of thepumping devices 16 so as to increase the quantity of additional medium introduced to each of the tubes. Similarly when the temperature of the steam generated by the tubes 4a, 4b, 4c, 4d drops below the desired 5 value, the deliveries of the pumping devices 16 are reducedso that the temperature of the gen erated steam is restored;: I

In order to supplement the efiect of the addi tional feeding by means of the devices 16, a

'means 14 for recording the temperature is provided between the tube system la-1c and the pipe system 4a-4d, which exerts an impulse through the conduit 15 on the main feed pump '2, sothat the feeding quantity is regulated in 15 'medium flowing from the-tube system 1dlcto the tube system iar-Ad; In'thisj case the regulaconstructed-and operated as'desired, and when; 33pumping devices are employed for. supplying the working; medium each; pumping device may be regulated by varying its speed or stroke. Alter-, natively, thegquantity or". working; medium may 35 belregulatedby varying the effective cross-secthe pumpingdevice which supplies it. Further, the main-supply oimediumdntroduced to the inlet end of the system may be efiectedbyseveral pumpingdevices in which case only one of such pumpingrdevices mayif desired be regulated.

What'I claim'is:

1. In a water tube steam generator ofthe type setgforth, incombination a plurality of preliminary heating tubes arranged inparallel and connected on the. one hand to a mainrfeed pipe and on' the other hand :to .a common delivery pipe, a

set, ofsecondary heating tubes .arranged in paral-1 lel andconnected to said common deliverypipe, means-for supplying additional working medium tmeachof sai'dsecondary heating tubes, devices associated. with said. secondaryfheating tubes by. means lof which, devices the .quantityof additional medium supplied to said secondary heating tubesv 5 is; regulatedin; accordance with the temperature regulating the main supply; of working medium fed to said preliminary heating tubesinaccordance-with-the temperature of the steamgenenated-in said secondary heating tubes, sothat not,

'"onlythe-main supply of working medium to the inlet end of the system but also additional supplies introduced at intermediate points in the. sev eraltubes of said secondary heating tubes are regulated, in accordance with: the temperature of the steam generated. i l j 2. In a, water tube steam generator of the type set, forth, in combination a plurality of prelimi- I nary heating tubes arrangedin parallel and connected on the one hand to a main feed pipe and 'onthe other hand toacommon delivery pipe, 9.: set of secondary heating tubes arranged in parallel and connected to said common delivery pipe, means for supplying additional working ;,medium to each of said secondary heating tubes, ""deyicesassociated with .said secondary heating dependence on the temperature of the working tion of the inlet ofthe suction or delivery pipe of 0f the steam generated in themyand means for tubes by means of which devices the quantity of additional medium supplied to said secondary heating tubes is regulated in accordance with the temperature of the steam generated in them, and means forregulating the main supply of working medium fed to saidpreliminary heating tubesfin accordance with the temperature of the steam generated in said preliminary heating 7 tubes.

3.. In a water tube steam generator as set forth in claim 1, the combination of said two sets of heating tubes with temperature-controlled de-- vices respectivelyassociated with said secondary heating tubes and adapted in accordance with the temperature of the steam generated in said secondary heating tubes to regulate not only the additional supply of medium fed to each of said secondary tubes but also the main supply of working medium fed to said preliminary heating tubes, the regulation of the main feed supply being effected after the limit oi. regulation of the additional supply has been reached.

.4. In a water tube steam generator as set forth in claim 2, the combination of said twosetsof heating tubes with temperature controlled devices respectively associated with the several.

tubes of said secondary heating tubes and: adapted to regulate the supplies of additional medium fed to said secondary heating tubes in accordance,

with the temperature of the steamgenerated in said secondary heating tubes, and a temperaturecontrolled device adapted to regulate the main supply of medium to said preliminary heating tubes in accordance with the temperature of the steam generated in said preliminary heating tubes.

5, In a water tube steam generator of the type set forth, in combination a pluralityv of preliminary heating tubes arranged in parallel and connected on, the one hand to a main feed pipeand on the other hand to a common delivery pipe, a

throttling device in said main feed pipe, a set of. secondary heating tubes arranged in parallel and.

connected to said common delivery pipe, a pipe,

branching from, said main feed pipe infront of.

said throttling device, deliverypipes leading from Y said branch pipe to eachflof said secondary heat-v motor, arranged in a pipe leading from, each of said,temperature-controlled devices to said'delivery pipes, a throttling device in eachof said tofsaid throttling devices'and branch pipes lead-- ing fromsaid temperature-controlled devices to acommonservomotor connected to said throt- I tling device in :said main feed pipe, so that the main supply of working medium to the inlet endof the. system as. well as the additional supplies nectedon the one hand to a main feed pipe and? on the other hand to a common delivery pipe, a"

throttling device in said main feed pipe, a setor secondary heating tubes arranged in parallel and'connected tosaid commondelivery pipe, a

pipe branching from said main feed pipe ahead of 1 said throttling device, delivery pipes leading from delivery pipes, pipes connecting said servomotors 1 said branch pipe to each of said secondary heating tubes for supplying additional working medium to each of said secondary heating tubes, a'

temperature-controlled device associated with each of said secondary heating tubes, a servomotor arranged in a pipe leading from each of said temperature-controlled devices to said de livery pipes, a throttling device in each of said delivery pipes, pipes connecting said servomotors to said throttling devicesand branch pipes leading from said temperature-controlled devices to a common servomotor connected to said throt-- tling device in said main feed pipe, so that the main supply of working medium to the inlet end of the system as well as the additional supplies introduced at intermediate points in the several tubes of said secondary heating tubes are regu-' lated in accordance with the temperature of the steam generated.

'7. In a water tube steam' generator of the type nary heating tubes arranged in parallel and connected on the one hand to a main feed pipe and onthe other hand to a common delivery 'pipe,

a temperature-controlled device in said common delivery pipe connected to a pump feeding said main feed pipe, a set of secondary heating tubes arranged in parallel and connected to said com-v mon delivery pipe, a pump connected to each'of said secondary heating tubes adapted to supply set forth, in combination a plurality of prelimiadditional working medium to each of said secondary heating tubes, a temperature-controlled 'device associated with each of said secondary 

